Propeller shafts and universal joints

l/,-TON 4 x 4 TRUCK (WILLYS-OVERLAND MODEL MB and FORD MODEL GPW)

Figure 32 -Distributor Wires

RA PD 305195

spring, then lift off breaker arm. Remove screw in stationary breaker point, and lift out point. (3) INSTALLATION. Place stationary breaker point in distributor, and install locking screw loosely. Lightly lubricate breaker arm pivot pin, and install breaker arm. Place spring in position with condenser lead, insert screw, and tighten securely in place. Aline points if necessary. To adjust points refer to step (1) above. e. Distributor Condenser. (1) DESCRIPTION. The condenser is attached by one screw to the support plate in the distributor, and connected by a short flexible wire across the distributor points. The condenser functions to absorb momentarily any current which has a tendency to arc across the points when they open. The condenser must be firmly attached to the 122

IGNITION SYSTEM

Figure 33-liming Marks (Flywheel)

RA PD 305193

support plate, and the cable in good condition. Refer to paragraph 62 c for tests. Test condenser on a condenser tester, if available. (2) REMOVAL. Slip off distributor cap clips and remove cap. Lift off rotor. Remove screw holding condenser to support plate. Remove screw in lead and remove condenser. (3) INSTALLATION. Position condenser on plate and attach with screw. Attach lead. NOTE: Determine if distributor points have been disturbed. Install rotor and cap.

6% IGNITION TIMING.

a. To Set Timing without Timing Light. Remove timing hole cover on engine rear plate at right side under cranking motor. Remove distributor cap. Crank engine to No. 1 cylinder firing stroke (distribu- tor rotor toward lower front corner of distributor). Set flywheel with ignition mark (fig. 33) in center of timing hole. Turn distributor housing so that breaker points are just opening, and tighten screw holding distributor to engine. Install timing hole cover. 123

I,!,-TON 4 x 4 TRUCK (WILLYS-OVERLAND MODEL MB and FORD MODEL GPW)

b. To Set Timing with Timing Light. Remove timing hole cover on engine rear plate at right side under cranking motor. Attach one lead of timing light to No. 1 spark plug, without removing the high- tension wire, and ground the other lead to the engine. Start engine and run slowly. Hold timing light in position to illuminate timing hole. Observe timing mark on flywheel, as illuminated by light, in relation to timing mark on engine plate. If marks do not coincide, loosen distributor clamp screw, and turn distributor housing in proper direction until marks do coincide. NOTE: Use mirror for a better view. Tighten clamp screw. Accelerate engine speed, and with light observe timing marks. They should separate to indicate that centrifugal spark advance is functioning.

66. IGNITION COIL.

a. Description. The ignition coil is mounted on the right side of the engine at the rear (fig. 21). A terminal is provided for the primary wire from the switch, a terminal for the primary wire to the distribu- tor, and a terminal for the high-tension wire to the distributor cap, and a ground strap connection. The coil steps up the primary cur- rent, furnished by the battery and generator, to high-tension current of sufficient voltage to cause a spark to jump the gaps of the spark plugs. b. Removal. Remove air cleaner by loosening clamp on flexible tube to carburetor; loosen wing nuts on air cleaner bracket at center of dash, and remove those on the right side. Pull secondary wire out of top of coil. Disconnect primary wires, then remove coil and bracket from engine, after which remove the bond strap. c. Installation. Attach bond strap to coil, and mount coil on engine with bond strap on coil bracket front stud, and tighten securely. Attach primary wires, and push secondary wire into top of coil. Install air cleaner, and tighten hose clamp.

67. SPARK PLUGS.

a. Description. Spark plugs (fig. 22) are located in the top of the cylinder head at the left side. The plugs are of the one-piece type. A copper-silver alloy gasket is used on each plug for heat transfer to the cylinder head, and to prevent leakage of compression. Push-on type wire terminals are used with radio filters at each plug. A spark plug insulator cap is fitted on each plug to protect the plugs from water and dirt. No shielding is used on the plugs. b. Adjustment. To adjust the gap, bend the side electrode only, and gage the plug with a round thickness gage to a gap of 0.030 inch. c. Removal. To avoid breakage of the porcelain, remove the plugs with the socket wrench and handle furnished in the vehicle tool equipment. d. Installation. Install new plug gaskets if available. Tighten spark plugs snug so that gasket will compress. 124

IGNITION SYSTEM

68. IGNITION SWITCH.

a. Description. On the earlier production, a key-type ignition switch was used which has been superseded by an interchangeable lever-type switch (fig. 5). Turn the switch lever clockwise for “ON” position. b Removal. Disconnect battery positive cable at battery. Unscrew retaining nut against face of instrument panel, and remove switch from panel. Disconnect wires and remove switch. c. Installation. Install the wires on proper terminals, then fit the switch into the hole in the instrument panel, screw on retaining nut, and tighten securely.

69. IGNITION WIRING.

a. Description. The ignition wiring (fig. 30) consists of low- tension and high-tension wires. The low-tension, or primary wires, carry the current from the ignition switch, which is connected to the electrical system of the vehicle, to the ignition coil, and from the coil to the distributor. The high-tension or secondary wires carry the high-voltage current generated in the secondary wires of the coil, to the distributor, where it is distributed to the spark plugs. No shield- ing harness is used. b. Removal. Before removing ignition switch wire, disconnect the battery negative (ground) cable. It is not necessary to disconnect the battery cable to replace the coil-to-distributor primary wire or the secondary wires. Disconnect wires at terminals, and remove wire or harness, opening wire clips on the harness in which the switch wire is a part. When removing secondary wires mark terminal tower in distributor cap for No. 1 cylinder spark plug. Pull wires out of dis- tributor cap and off spark plug terminals. c. Installation. To install primary wires, run wire or harness through clips, and attach terminals securely. Install secondary wires, for spark plugs, through support bracket. Push terminals down well into the proper distributor towers (fig. 32). Push rubber secondary wire tip down in place on distributor towers. Push terminals down on proper spark plugs. Refer to firing order (par. 62 b).

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